fema-mcp-server AGENTS.md

Developer Protocol

Server: fema-mcp-server Version: 0.1.14 Framework: @cyanheads/mcp-ts-core ^0.12.3 Engines: Bun ≥1.3.0, Node ≥24.0.0 MCP SDK: @modelcontextprotocol/server ^2.0.0 Zod: ^4.4.3

Read the framework docs first: node_modules/@cyanheads/mcp-ts-core/CLAUDE.md contains the full API reference — builders, Context, error codes, exports, patterns. This file covers server-specific conventions only.

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Core Rules

• Logic throws, framework catches. Tool/resource handlers are pure — throw on failure, no try/catch. Plain Error is fine; the framework catches, classifies, and formats. Use error factories (notFound(), validationError(), etc.) when the error code matters.
• Use ctx.log for request-scoped logging. No console calls.
• Use ctx.state for tenant-scoped storage. Never access persistence directly.
• Need input the caller didn't supply? return ctx.requestInput(...) and read ctx.inputs when the handler is re-entered. Never await for user input mid-handler.
• Secrets in env vars only — never hardcoded.
• Close the loop on issues. When implementing work tracked by a GitHub issue, comment on the issue with what landed and close it. Do both — a comment without a close leaves stale issues open; a close without a comment leaves no record of what shipped. The comment is for future readers — state the concrete changes, not the conversation that produced them.

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Patterns

Tool

import { tool, z } from '@cyanheads/mcp-ts-core';

export const femaSearchDisasters = tool('fema_search_disasters', {
  description: 'Search federal disaster declarations by state, incident type, declaration type, and date range.',
  annotations: { readOnlyHint: true, openWorldHint: true },
  input: z.object({
    state: z.string().length(2).optional().describe('Two-letter US state code (e.g. TX)'),
    limit: z.number().int().default(20).describe('Max results (1–1000)'),
  }),
  output: z.object({
    declarations: z.array(z.object({
      disasterNumber: z.number().describe('Unique FEMA disaster number'),
      declarationTitle: z.string().describe('Official disaster title'),
      state: z.string().describe('Two-letter state code'),
    })).describe('Matching disaster declarations'),
    count: z.number().describe('Total matching records'),
  }),

  async handler(input, ctx) {
    const results = await getOpenFemaService().searchDisasters(input, ctx);
    ctx.log.info('Disaster search completed', { state: input.state, count: results.count });
    return results;
  },

  format: (result) => [{
    type: 'text',
    text: result.declarations.map(d => `**${d.disasterNumber}**: ${d.declarationTitle} (${d.state})`).join('\n'),
  }],
});